Bag forming, filling and sealing method and apparatus

ABSTRACT

A method and apparatus for forming, filling and sealing thermoplastic bags, the bags being formed by intermittently passing a heated knife or the like transversely through the strip, as the strip moves through a linear path. The knife both partially severs and seals along the line of severance, the bags being defined between these lines of severance. The strip may be either of tubular or overfolded sheet stock. If tubular, a blade slits one edge open to form a mouth for the bags while, if overfolded sheet stock, the free edges define such a mouth. The bags then continue along the linear path past a filling device which inserts material to be packaged therein, and past a sealing device which seals the filled bags. The selvage portion above the seal is removed as the bags continue along the linear path. If desired, one or more transverse lines of seal but not severance are formed between the lines of seal and severance, these lines of seal but not severance forming one or more compartments within each bag.

United States Patent [191 Membrino BAG FORMING, FILLING AND SEALING METHOD AND APPARATUS.

Primary Examiner-Travis S. McGehee A tmrney- Arthur A. Jacobs [451 Aug. 21, 1973 5 7] ABSTRACT A method and apparatus for forming, filling and sealing thermoplastic bags, the bags being formed by intermittently passing a heated knife or the like transversely through the strip, as the strip moves through a linear path. The knife both partially severs and seals along the line of severance, the bags being defined between these lines of severance. The strip may be either of tubular or overfolded sheet stock. If tubular, a blade slits one edge open to form a mouth for the bags while, if overfolded sheet stock, the free edges define such a mouth. The bags then continue along the linear path past a filling device which inserts material to be packaged therein, and past a sealing device which seals the filled bags. The selvage portion above the seal is removed as the bags continue along the linear path. If desired, one or more transverse lines of seal but not severance are formed between the lines of seal and severance, these lines of seal but not severance forming one or more compartments within each bag.

7 Claims, 11 Drawing Figures PAIENIEIIMZI B13 SHEET 10F 3 INVENTOR HERCUL ES MEMBRINO ATTORNEY BMW INVENTOR HERCULES MEMBR/NO BY ATTORNEY PAIENIED m 973 SHEEI 3 0i 3 VQN Q 6BR QNN mw r g IN VEN TOR HERCULES MEMBR/NO A T TORNEY BAG FORMING, FILLING AND SEALING METHOD AND APPARATUS This is a continuation-in-part of co-pending application Ser. No. 44,186, filed June 8, 1970.

This invention relates to a method and means for forming, filling and sealing bags, and it particularly relates to bags constructed at least partially of thermoplastic materials.

In the aforesaid co-pending application an apparatus and method was described whereby thermoplastic bags, which were connectedin a strip by means of integral connecting nips, were filled and then sealed while the strip moved through the mechanism. After the bags were filled and sealed, they were separated from each other by breaking the connecting'nips. This provided a rapid and efficient filling and sealing process. However, it was necessary to have the strip of bags formed in a prior operation before they could be filled and sealed. Two completely separate and distinct operations were therefore necessary.

It is an object of the present invention to improve over the aforesaid process by providing a method and apparatus which, in one operation, not only fills and seals the bags but also forms them prior to the filling and sealing steps.

Another object of the present invention is to provide a method and apparatus of the aforesaid type which is capable not only of forming, filling and sealing bags in a strip but is also capable of forming compartmented bags and filling and sealing the compartments.

Another object of the present invention is to'provide a method and apparatus of the aforesaid type wherein the bags may not only be formed with compartments but both the bags themselves and the compartments therein may be varied in size as required.

Other objects and many of the attendant advantages of this invention will be readily appreciatedas the same becomes better understood by reference to the following description when read in conjunction with the accompanying drawings wherein:

FIG. 1 is an elevational view of an apparatus, embodying the present invention, for operating on tubular stock.

FIG. 2 is a sectional view taken on line 2-2 of FIG. I.

FIG. 3 is a sectional view, taken on line 3-3 of FIG. 2.

FIG. 4 is a sectional view taken on line 4-4 of FIG. 1.

FIG. 5 is a somewhat schematic view of the cam actuated electrical circuit.

FIG. 6 is an elevational view of another embodiment of the present invention.

FIG. 7 is a fragmentary perspective view of a tubular stock strip formed with compartments such as are provided by using the forming mechanism of FIG. 6.

FIG. 8 is an elevational view of an apparatus similar to that shown in FIG. 1, but modified to operate on flat sheet stock.

FIG. 9 is a fragmentary perspective view of a flat sheet stock type material formed by the apparatus of FIG. 9.

Referring now in greater detail to the various figures of the drawings wherein similar reference characters refer to similar parts, there is shown in FIG. 1 an apparatus, generally designated 10, comprising a spool 12 upon which is wound a strip 14 of tubular material made of thermoplastic, such as polyethylene, polypropylene, or the like; The spool 12 is positioned by gravity on a supporting disc 16 mounted on a spindle 18 which is supported on a table 20. I

The tubular strip 14 passes over a mandrel 22 to which is connected a blade 24. The mandrel is formed integral with a feed chute 26 and may be either a single hanger bar or a double armed bar, such as disclosed in the aforesaid co-pending application wherein the arms incline laterally outwardly from an apex on the upstream end to a widened position connected to the chute. The lower end of the chute 26 projects below thee upper edge of the strip 14.

A sealing roller 28 is provided downstream of the chute 26, below the upper edge of the strip 14, and this roller is'mounted on a shaft 30 which is provided with a gear (not shown) within gear box 32. This gear is in mesh with drive gearing (not shown) within gear box 32, which is, in turn, engaged with a gear (not shown) mounted on the drive shaft of an electrical motor 34.

The roller is heated by any standard means desired, as, for example, by containing an electrical resistance operatively connected to a source of electrical energy through commutation means or the like, and is arranged to co-act with a back-up roller 36 (see FIG. 4), constructed of heat-resistant material, which is mounted on a shaft 38.

Downstream from the rollers 28 and 36 is a horizontal slitter blade 40 mounted on a bracket 42 connected to a standard 44 mounted on the table 20.

Downstream from the blade 40 are a pair of oppositely-disposed draw rollers, only one of which is shown at 46. The draw roller 46 is mounted on a spindle 48 which is connected through a magnetic clutch assembly 50 to a drive shaft 52. The drive shaft 52 is connected through appropriate gearing (not shown) in a gear box 54 to an electrical motor 56.

Between the spool 12 and the blade 24 is provided a forming device, generally designated 58. The forming device 58 comprises a backer plate 60 having an anvil portion 62 constructed of heat-resistant material. Pivotally connected relative to the backer plate 60 is a sealing plate 64. The plate 64 is provided with a knife 66 which is heated by any desirable means, but preferably by means of an electrical resistance 68 connected to a source of electrical energy by any desirable means such as by a flexible cable(not shown). Although not shown, a similar heating means may be used in the backer plate 60, whereby additional sealing heat may be applied for thicker or heavier sheet material.

A solenoid device 70 is connected to the pivoted plate 64. This solenoid 70 is actuated in timed relation with the draw rollers 46 and the feeding mechanism as will hereinafter be described. Although a solenoid mechanism is here illustrated and described as one method of accomplishing the purpose, any other standard mechanism may be substituted for accomplishing this purpose. The lower end of the forming device 58 is provided with a nut portion 72 having a threaded aperture within which is engaged a threaded rod 74. The rod 74 is supported for rotation between a pair of journals 76 fixed to the table 20 and is provided with a handle 78, whereby the rod 74 may be actuated to adjust the forming device relative to the spool and feed chute, thereby varying the widths of the bags.

The feed chute 26 is provided with a star wheel 80 actuated by an electrical motor 82. Also mounted on the shaft 84 of the motor 82 is a cam disc 86 (see FIG. The cam disc 86 is provided with a plurality of equidistantly-spaced nose portions 88. These nose portions 88 are adapted to coact with a normally closed switch 90 and a nonnally open switch 92. The normally closed switch 90 is in electrical circuit with the magnetic clutch 50 while the normally open switch 92 is in electrical circuit with the solenoid 70.

The motor 82 actuates the star wheel 80 in a pre-set timed rotation to correspond to the movement of the strip 14, the material to be fed being fed by each vane of the star wheel. The nose portions 88 are arranged to correspond with the vanes of the star wheel so that just prior to a vane being in a position to feed material, a nose portion 88 opens the switch 90 to deenergize the clutch 50 and stop the rotation of the draw rollers 46. This provides a dwell time in which the feeding takes place.

At the same time, the oppositely-disposed nose portion 88 closes the switch 92 which activates the solenoid 70 to push the knife 66 toward the anvil plate 62 and thereby sever and simultaneously seal the severed edges on either side of the cut. This forms the next successive bag in a series, these bags being thereby initially formed from raw stock. However, since the knife 66 stops short of the upper edge of the tubular strip, it leaves a connecting edge portion 94 which overlaps the mandrel 22 that serves as a hanger means for the formed strip of bags.

Since the strip 14 is tubular material, it is necessary to form a top opening or mouth in the bags before they reach the feed chute 26. This is automatically accomplished by the blade 24 which slits the top open first before the bags reach the chute. By the time a bag is completely slit open at the top, it has enwrapped the lower portion of the chute which holds it in position for filling. After filling, and before the bag completely leaves the chute, the sealing roller 28 has formed a linear seal, as shown at 96 in FIG. 1, which reconnects the bags, while sealing the mouths thereof.

The linear seal 96 forms a selvage portion 98 above the seal. This selvage portion is removed by means of the horizontal blade 40 which automatically slices through the seal 96. However, this slicing takes effect only while the upstream bag is still partially connected to the selvage portion and the downstream bag is held between the draw rollers 46.

After the selvage portion 98 is completely removed and wound up on a spool or the like (not shown), the completely formed, filled, sealed and separated bags, such as indicated at 100, fall into a bin or the like.

In FIG. 6 there is shown a modification of the apparatus of FIG. 1 wherein the device, generally designated 110, is almost identical to that of FIG. 1, including the table 112, the spool 114, the blade 116, the chute 118, the heated roller 120 and back-up roller opposed thereto (not shown), the horizontal blade 122, and the draw rollers 124 actuated by the magnetic clutch 126. However, the forming device 128 is somewhat different from the forming device 58.

The forming device 128 comprises three separate units respectively designated 130, 132 and 134. The

unit 134 is a sealing and severing knife assembly similar to the unit 58 of FIG. 1. However, the units and 132, although the same as unit 58 in other respects, have flat heads in place of the knife 66 so that instead of cutting through the strip, they only form lines of seal, as shown at 136 in FIG. 7. In this manner, as each bag is formed, the knife of unit 134 forms a line of both seal and severance, as indicated at 138 in FIG. 7, while the flat sealing heads of units 130 and 132 form individual compartments, as indicated at 140 in FIG. 7.

The bag units formed by the forming device 128, these bag units being designated 142 in FIG. 7, are used to package a plurality of different items in one bag. For example, one compartment may contain screws, another compartment may contain bolts, and the third compartment may contain washers. However, since the items contained in one compartment may require more space than the items in another compartment, it may be desirable to vary the widths of the compartments within a single bag. This is accomplished in the apparatus of FIG. 6 by making each unit separately laterally adjustable relative to the others. For'this purpose, each unit is mounted on a bed plate, respectively designated 144, 146 and 148; each bed plate being slidable on the table 112. The table 112 is provided with an elongated slot 150 through which extends respective bolts 152, 154 and 156 attached to their respective bed plates. The bolts are provided with washers, respectively designated 158, 160 and 162 which bear against the bottom of the table 1 12 and coact with the bolts to hold the individual units 130, 132 and 134 in individually adjusted positions. Gauges or other desirable measuring devices may be provided on the table 112 to measure the amount of adjustment of each unit.

Although three units are illustrated as comprising the forming device 128, as many units may be used as desired in accordance with the number of compartments desired. Furthermore, regardless of the number of units provided, any one or more, except for the cutting unit, may be made inoperative when so desired.

Each unit 130, 132 and 134 is provided with a solenoid assembly, as at 164, 166 and 168, similar to that shown at 70 in FIG. 1. These solenoids each act in synchronism with the magnetic clutch 126 in the manner illustrated in FIG. 5. In this respect, there are three separate star wheels, respectively designated 170, 172 and 174 in the chute 118, each star wheel coacting with a separate chute outlet. However, the star wheels are all operated in timed relationship by a single electrical motor, such as shown at 82 in FIG. 1, through appropriate standard gearing (not shown).

In FIG. 8, there is illustrated another embodiment of the invention wherein the apparatus, generally designated 200, is identical to that shown in FIG. 1, including a table 202, a spool 204, a blade 206, a chute 208, a sealing roller 210 and back-up roller (not shown), a horizontal blade 212 and draw rollers 214 actuated by a magnetic clutch 216. The only difference is that instead of the forming device 58, there is provided a forming device 218 which is adapted to operate on flat, overfolded stock 220 (as shown in FIG. 9).

Since the flat sheet stock is open at the top, there would be nothing to hold it draped over the mandrel if the forming device 58 were used. Therefore, the forming device 218, which is, in other ways, similar to the forming device 58, is modified to provide a heated blade portion 230 which is provided with a recess 232 adjacent to but spaced from its upper end. This recess prevents cutting through the strip at that area and leaves an unsevered nip 234 (see FIG. 9). This nip retains the bags in the strip until the selvage portion is severed by the blade 212, and also overlaps the mandrel so that the mandrel acts tosupport the strip of bags.

It is also possible to make compartmented bags from overfolded flat sheet stock by using the same apparatus shown in FIG. 6 but forming a recess, such as recess 232, in the knife portion of the unit 134. A strip of compartmented bags formed in this manner is illustrated in FIG. 11 where the individual bag units 236 are each provided with compartments 238 and are connected to each other by nips 240 which act as connecting means between the bags and as supporting means when draped over the mandrel in the same manner as nips 234.

As described above, either tubular material or overfolded flat sheet stock may constitute the strip. Both types are generically designated as double-ply material since both have a pair of walls adapted to define the opposed side walls of the bags.

The invention claimed is:

1. An apparatus for forming, filling and sealing bags in a strip, said apparatus comprising a supply means and a strip moving means, said supply means being spaced from said strip moving means, to define a path of linear movement of a strip therebetween, said supply means being constructed and arranged to hold a supply of a thermoplastic double-ply strip while said strip is being moved from said supply means along said linear path, a forming means interposed in said linear path, said forming means comprising a heated cutting means disposed transversely of the width of said strip, said cutting means being constructed and arranged to form laterally spaced lines of seal and severance along the length of said strip as said strip travels along said linear path, said lines of seal and severance leaving an unsealed portion adjacent one edge of the strip, between the successive bags formed by said lines of seal and severance, a mandrel constructed and arranged to support the bags by means of said unsealed portions as said bags continue their travel from said forming means along said linear path, severing means situated downstream from saidforming means for cutting said bags to form mouths, a feed means for filling said-bags through said I mouths of said bags, said feed means being situated downstream from said severing means, said feed means being constructed and arranged to be at least partially enveloped by the mouths of said bags, a heated sealing means situated downstream from said feed means, said sealing means being constructed and arranged to form a line of seal to close the mouths of said bags after they have been filled, and a slicing means situated downstream from said sealing means, said slicing means being constructed and arranged to sever the filled bags from a selvage portion formed at the opposite side of said line of sea] from said bags.

2. The apparatus of claim 1 wherein said supply means is a spool upon which the strip is adapted to be rolled, and said strip moving means comprises a draw roller mechanism for drawing the strip from the spool.

3. The apparatus of claim 1 wherein said forming means is intermittently activated and deactivated in timed sequence with the deactivation and actuation of said strip moving means.

I 4. The apparatus of claim 1 wherein said strip moving means is a draw roller assembly comprising at least one draw roller which is operatively connected to a drive motor by a clutch, said forming means being operatively connected to an actuating means, said actuating means being operatively connected to said clutch to move said forming means in timed relationship with said clutch, said actuating means being operatively connected to a movable feed device situated in a feed chute, said feed device and feed chute constituting said feed means, whereby said feed device, said clutch and said forming means are actuated in timed relationship with each other.

5. The apparatus of claim 1 wherein said forming means is adjustable relative to said supply means along said linear path. 1

6. The apparatus of claim 1 wherein said forming means comprises, in addition to said cutting means, at least one transverse sealing means constructed and arranged to form a line of seal in spaced lateral relationship to said cutting means, whereby at least two compartments are formed in each bag.

7. The apparatus of claim 6, wherein the cutting means and the transverse sealing means' are constructed and arranged for lateral adjustment relative to each other. 

1. An apparatus for forming, filling and sealing bags in a strip, said apparatus comprising a supply means and a strip moving means, said supply means being spaced from said strip moving means, to define a path of linear movement of a strip therebetween, said supply means being constructed and arranged to hold a supply of a thermoplastic double-ply strip while said strip is being moved from said supply means along said linear path, a forming means interposed in said linear path, said forming means comprising a heated cutting means disposed transversely of the width of said strip, said cutting means being constructed and arranged to form laterally spaced lines of seal and severance along the length of said strip as said strip travels along said linear path, said lines of seal and severance leaving an unsealed portion adjacent one edge of the strip, between the successive bags formed by said lines of seal and severance, a mandrel constructed and arranged to support the bags by means of said unsealed portions as said bags continue their travel from said forming means along said linear path, severing means situated downstream from said forming means for cutting said bags to form mouths, a feed means for filling said bags through said mouths of said bags, said feed means being situated downstream from said severing means, said feed means being constructed and arranged to be at least partially enveloped by the mouths of said bags, a heated sealing means situated downstream from said feed means, said sealing means being constructed and arranged to form a line of seal to close the mouths of said bags after they have been filled, and a slicing means situated downstream from said sealing means, said slicing means being constructed and arranged to sever the filled bags from a selvage portion formed at the opposite side of said line of seal from said bags.
 2. The apparatus of claim 1 wherein said supply means is a spool upon which the strip is adapted to be rolled, and said strip moving means comprises a draw roller mechanism for drawing the strip from the spool.
 3. The apparatus of claim 1 wherein said forming means is intermittently activated and deactivated in timed sequence with the deactivation and actuation of said strip moving means.
 4. The apparatus of claim 1 wherein said strip moving means is a draw roller assembly comprising at least one draw roller which is operatively connected to a drive motor by a clutch, said forming means being operatively connected to an actuating means, said actuating means being operatively connected to said clutch to move said forming means in timed relationship with said clutch, said actuating means being operatively connected to a movable feed device situated in a feed chute, said feed device and feed chute constituting said feed means, whereby said feed device, said clutch and said forming means are actuated in timed relationship with each other.
 5. The apparatus of claim 1 wherein said forming means is adjustable relative to said supply means along said linear path.
 6. The apparatus of claim 1 wherein said forming means comprises, in addition to said cutting means, at least one transverse sealing means constructed and arranged to form a line of seal in spaced lateral relationship to said cutting means, whereby at least two compartments are formed in each bag.
 7. The apparatus of claim 6, wherein the cutting means and the transverse sealing means are constructed and arranged for lateral adjustment relative to each other. 